I did this from a Treo 680 to a BlackBerry, and I also had my life mapped out on my Palm. The switch was easy and the best one I ever did. The most effective way to get stuff moved from Palm to BB is to use MS Outlook. Sync everything on the Palm to Outlook, then sync the BB to Outlook. Completely painless.

Remember to go the extra mile and get a BlackBerry data plan with your new BlackBerry. It makes all the difference in your user experience.

I also migrated from a Palm (Tungsten though) to a BlackBerry. Smooth transition, no problems bringing over data from Palm (with the exception of Notepad - the one that you can make drawings with your stylus). Initially I preferred Palm's desktop manager which I felt was a bit more user friendly. But since making the switch to BlackBerry and using Outlook, I wish I had changed sooner.